Air-brake lock



B. w. wEsTB March 23 1926.

AIR BRAKE LOCK zshets-sneei 1 Filed March 9. 1925 mvENToR y ,550m/nwo IM M/ffrao March z3 192s. 1,577,855'

. B. W. WESTBO AIR BRAKE LOCK Filed March 9, 1925 2 sheets-sheet 2 v 2z @IgM-, /05 g 0 n lmlnl 0' v 27 Illlllllll ATTORNEY CII Patented Mar. 23, 1926.

UNITED stars 1,577,855 rear Irice.-

IBERNHARD W. WESTBO, OF SOUTH PRRIE, WASHINGTON, ASSIGNOR TOKBALWAY SAFETY BRAKE LOCK COBJPORATION, GIF TACOMA, WASHINGTON.

AIR-BRAKE LOCK.

Application filed March 9, 1925. Serial'Ne. 14,090.

To all whom t may concern.'

Be it known that I, BERNHARD lV. lVns'rno, a citizen of the United States, and a resident Ott South Prairie, Pierce County, -Washington, have invented certain new and useful Improvements in Air-Brake Locks, et' which the following is a speciiication.

This invention relates to improvements in air brake mechanism and more particularly to an air brake locking mechanism that operates automatically to prevent the release of a brake incidental to a reduction of presire in the brakecylinder due to leakage, exhaustion of supply or accident to pipe connections.

The principal object oit this invention is to simplify the construction of the mechanism illustrated and described in the application for patent on air brake lock `tiled September 10, 192i, under Serial No. tf 854i.

To better explainthe purpose of the invention, I will state that the present locking .mechanism is intended for use in connection with the air brake as now used on railway rolling' stock and which is a combination of parts'controlled and operated by con'ipresseo air. More specifically stated, such mechanism consists of a source of compressed air supply, a brake valve by means of which an engineer can supply or release the brakes, a brake pipe, or train line, by means of which connection is made between the brake valve and brake apparatus of each car in a train, a brake cylinder by means of which the power stored in compressed air may be transformed into mechanical "force to a brake gear consisting of various rods, brake shoes and other required connections` whereby the brake shoes may be applied to the wheels of a car to retard it.

In connection with the above parts there is also included for each separate vehicle., an auxiliary reservoir in which a supply of compressed air is sto-red suiicient to operate the brake on that vehicle, a tripple valve to which the brake pipe, auxiliary reservoir and brake cylinder are connected and which serves to control thel flow ot air from the brake pipe to the auxiliary reservoir when charging, from the auxiliary reservoir to the brake cylinder when applying and from the brake cylinder toatmosphere when releasing the brake. tvhen the brakesqare nel: being used, the train pipe and ausiiiia'y raser:z

voir are charged and maintained at a fixed normal pressure. rlhe brakes are applied by reducing the pressure in the train. pipe below thatin the auxiliary reservoir. duction is caused by an opening' being made from the train pipe, or itsconnections, to' atmosphere and may be intentional ask when the engineer opens the brake valve or ac t f cidentally asin case oit the ln'eaking oit a pipe or hose. v

To those.familiarwith train operations, it is known that ita train of cars equipped with air brakes is disconnected from 'the en- Vgine which furnishes the source ot air'supply, the-'brakes ot all -cars will be applied for the reason that opening the train line destroys the equality .of train line and auxtrain happens to be standing on a grade'it may start t0 roll unless the hand brakes, with which .cars are usually equipped, have been set. Y l Y t It is 'further known that the air supply of' trains somtimes is used faster than it can be supplied. This is most apt to occur with heavy trains operating on long down grades, and when such does occur the hand brakes must be resorted vto and depended upon entirely until the supply oi air can againbe built up. p

In view ot these undesirable results, due to air leakage or exhaustion of supply, Ait has been the object of this invention to provide automatically operating locking means for use in connectionwith ,brakes et the above character that will move into position -for holding a brake when. set should the pressure of air in the brake cylinders. `ter any reason fall below a certain pre-determined amount and which ,will` move to non functional position when a sate working pressure has again been built up in the auxiliary reservoir.

Another object of the invention resides in the provision of locking devices, as above stated, that may be manually set or released and which maybe installed on the regular brake equipment et railway 'cars Without alf proved details oi construction, the preferred forms of which are illustrated in the accompanying drawings, wherein- Figure 1 1s a fragmental side elevation of a car equipped with air brake mechanism and a lock therefor in accordance Vwith de- Vtails of the present invention.

Figure 2 is a plan view, partly in section, ot parts of the braking` mechanism.

`Figure 3 is an enlarged, side view of the locking mechanism.

Figure i is a plan of the same.

Figure 5 is an enlarged sectional view of the valve mechanism `used in connection with the lock, and which controls the lecking pawl.

Referring more in detail to the drawings- 1 designates what may be a railway car, equipped with air brake mechanism ot' that type in connection with which the present automatic locking` device is used. The air brake mechanism is oil' the usual form now generally used on all railway cars and consists principally of the train pipe 2, through which compressed air is delivered from a source of supply, not shown, along` the train to the individual brake mechanism of each car, and auxiliary reserver 3 that is connected so as to be charged from the train vline through a pipe 4 vand an interposed Vtripple valve mechanism, designated at 5, and a car brake cylinder G that receives its air from the auxiliary reservoir, under control of the tripple valve.

lVithin the brake cylinder 6 is a piston 7 adapted to be moved outwardly against the resistance ot a coiled spring 7 by the admittance of air to the cylinder and lined to the piston is a rod 8 which, at its outer end, connects pivotally as at 9, with a lever 1() to which in turn are connected rods or cables 11 and 12 extended to the brake beamsJ or corresponding parts, not shown, at opposite ends of a car and which carry brake shoes that are adapted to be pressed into engagement with the car wheels when it is desired to retard oi stop the car. The piston rod 8 connects with the lever l() at a point approximately two-thirds of the distance between its ends and the rods 11 and 12 are pivotally attached to the lever, respec tively, at the extreme end of the longer section and intermediate this end and the pivotI connection with the piston rod, the parts operate so that when air is admitted from the auxiliary reservoir to cylinder 6 which drives piston 7 and rod S outwardly, the lever 10 is se moved as to cause brakinr tension on both rods 11 and 12.

rl'he lockingv mechanism embodied bythe present invention is mounted-upon a base plate 20 which is vertically disposed again the side of brake cylinder G and is i'ixed thereto by means oie bolts 21 extended through a laterally turned flange 22 along the top edge o1c the plate and a supporting flange 23 formed, integral with the cylinder G. rlhese bolts may also serve to support the brake cylinder from the car structure.

Cast integral with the plate 2O at its opposite side edges are guides 2st and 25 through which a lock bar 2G is slidably eX- tended. Along its upper edge the bar is provided with ratchet teeth 27 and near one end it has a loop 2i" into which one end oi' the brake lever 10 extends and wherein it is lixed by a pivot pin 28. rilhe connection and mounting of the parts is' so arranged that the lock bar slides back and forth in its mountings in accordance with the movement oi' the lever 10 as influenced by the hand or air brake.

To the outer end oi' the lock bar 26 a cable 13 is attached which extends to the hand brake shaft 16 at the end of the car. This cable may be wound on the shalt by rotation of the brake wheel 17 at its upper end i't' it is desired to set the brake by hand.

Pivotally lined to the base plate 20 by means of a bolt 30 is a locking dog 31 havingl a pivotally mounted pawl 32 atl its end adapted to ho'lding'ly engage with the teeth 27 of the locking bar. Normally, that is when there is sutticient air pressure in the auxiliary reservoir 3 to hold the brakes set,

the locking means is not needed and the pawl is held disengaged from the teeth of the locking bar by means presently described, but as soon as this pressure approaches the point at which it will become 'insullicient to hold the brake, the pawl is permitted to move into holding engagement with the teeth of the lock bar so that the latter cannot move inwardly and the brake beamwill be held thereby so that the brakes cannot be released.

The means. just referred to for controlling,` movement o't the locking' dog, as best shown in Figures l and 5, consists oit a plunger 35 connected at it lower end with a piston operable in an air cylinder 37 under the control ot air in the auxiliary reservoir. At the upper end oit the plunger is a head 3S adapted, when the plunger is extended, to engage with a roller 39 supported by a pin 4i() from the dog to thereby litt the dogg' and locking,1 pawl from the rack teeth. Vfhen the plunger retracts, the dog' is Jfree to crop to permit the pawl to lock with the rack bar.

,An important feature of the inventioirre lili sides in the construction and manner oi mounting the pawl on the locking dog which permits it to be easily released regardless ot the amount et holding pressure against it. The pavvl is pivotally mounted on the pin thatin-ounts the roller 39. Its upward pivotal movement is limited by contact With an adjusting screw 41 that is threaded through an extension 42 `from the end of the dog overlying the pawl. A coiled spring 43 located about the pin 40 bears against the pawl to retain it yieldingly in place but when pressure is exerted by the plunger up Wardly against the roller the locking device Will hinge upwardly at the pivot point 40 and thus the lock bar will be released. As

soon as the paul is disengaged 'from the rack, the spring 43 brings it back to normal position. lVithout this feature of construction, an excessive amount ot' pressure would be required to release the pawl itt there 1s any tension on the brake beam.

The air cylinder 87 has a supporting "flange 45 through which bolts 46 are ex- `seat 72 at the end of the channel.

tended to lix it to the plate 2() and formed integral with the lowerend ot cylinder 37 is a horizontally directed valve housing47 having al central passage 48 coninninicating with each end ot the housing and which is connected with the lower end oit cylinder 37 by means ot a channel 49.

Connected with one end of the housing 4T through the ijntermediacy of nipples 50 and 5l and union 52,.is a pipe 53 that connects with the train line pipe 2. This pipe ias y communication With the cylinder 37 through channels 48 and 49. A valve member is located in the inner portion of nipple 50 and channel 48 comprising a stem portion and integral collar 56.; the latter' being adapted to a tapered seat 57 about the Aouter end of channel 4S to close the latter against air from the train line. A spring 5S coiled about the outer part of stein 55 and hearing against nipple 50 yieldingly retains the valve closed.

Threaded part Way into the other end of the valve housing 47 is a sleeve 60 and onto theouter portion of this is threaded a fitting G1 provided with a `flange G2 at its outer end onto which a cap 63 is threaded. A flexible diaphragm 64 is clamped between the end oit tilting (il and the cap and a pipe (i5, leading lroin the auxiliary reservoir, connects with the cap through the interme vdiacy ot nipple 66 and union 671 Located within the channel 4S is a valve mechanism comprising a valve stem 70 and an integral collar 7l adapted to a tapered The inner endet this stem engages with the inner end of stein 55 and these are et such length that when valve 56 is closed, the valve "Tl Vwill be opened, and vice versa. The outer 'end of valve stem 70 is threaded into a head portion 74 which seats against the inner tace of diaphragm 64 and is yieldahly held against inward movement by means ot a coiled spring 75 that bea-rs against the inner face oi' headv Z4 and inner end portion ot' sleeve 60. This spring normally retains the valve il open sol thatthere is 'tree passage ot air troni cylinder 37 through channel 49 and channel 48 into the chamber 7G just Within the inner end of sleeve and this chamber has an opening 77 to atmosphere through its lower side Wall as shown in Figure 5.

lilith the device so constructed it will operate as follows: llllhen the auxiliary reservoir is charged to a' suitable Working pressure, this pressure will be connnunicated through pipe against the outer .tace et diaphragm 64 causing the latter to nieve in- `wardly against pressure of spring to seat valve 7i and to open valve 56 so that there is a direct coinnninicatien between the` train pipe and cylinder S? through pipe 5S and channels 4 8 and 49. The air pressure from the train line acts against the piston 36 and moves itV upiva'rdly causing head 3S to engage the roller 3f.) onilog 3l. and to litt and hold the pawl 32 free ot ratchet bar 2S.' rlh'us, so long as there is a desired Working pressure in the train line and auxiliar-y reservoir the brake mechanism operates the samev as il the present device were not used.

Assun'iing then that the bralre et al'ear has been set by air and that for some reason such as a leakage or exhaustion oi supply, the pressure of air in the auxiliary reservoir approaches a point at which it would be insufi'icient to hold the bralesset, the spring 75 overcomes the pressure against the diaphragm G4 and pushes the head T4 outward ly thereby opening valve 7 land permitting valve 56 to close. As soon as valve 7l opened the air trom cylinder 37 escapes to atmosphere through channel4-9, channel 48, cha1nher76 and port 77. The spring contained Within cylinder 37 and bearing downwardly ou'the piston moves the plungerh downwardly thereby releasing the dogi so that paivl 32 will drop into locking contact with teeth ot bar 2li to prevent the release ot the brake. lVhen the auxiliary reservoir is recharged to a safe ordesirahle pressure the diaphragm 64 will be pushed inwardly, overcoming spring` 75 thereby sealing valve 7i and opening valve 5G so that air troni the train line will again act on piston Se to release the pawl Vfrom the locking bar 9.6.

For the purpose ol manually releasing the dog from the lock bar by4 a person on. top ot the car, l have provided a bell crank lever that is pivot-ally Fixed by a bolt 91 to plate Q0. This crank has an arm V92 extended beneath the roller' S9 on the dog` 3l and another arm 93 extending u nvardly tov which al chain 94 is attached. fhia chain lli@ fig. I

connects with one arm of a bell crank J pivotally mounted at the end of the car. A rod 96 is fixed to this latter crank and extends upwardly through suitable guides to point adjacent the hand brake wheel. By pressing downwardly on this rod the cranl: arm 92 will be thrown upwardly against roller 39 to disengage the paw 32 from the teeth of the rack or lock bar. Spring 9T connected with bolt and arm 93 retains it to normal position.

To permit the manual release ot the lock by a person at either side of the car, l have provided an shaped release lever lOO that is pivotally supported in horizontal position by holt 1.01 'treni plate 20. Rods 102 and 1025 are attached to its opposite ends and these are extended to o l' posite sides of the car. One arm of this lever` is fixed to chain -94 in such manner that pull on either rod lOl or 102 will roel: the lever and through chain Uil will actuate bell crank 90 to litt the dog and pawl from the lock bar 26.

lVhen the car is entirely disconnected from a sourceot compressed air, the brakes may beoperated by the hand brake in the usual manner and will be locked when setby the presentlockiug device.

It will be noted that the tension of spring may be varied by adjustment ot sleeve G0 so that the locking device will be released or set at any desired pressure in the auxiliary reservoir.

Having thus described my invention, what I claim as new therein and desire to secure by Letters-Patent, is:

1. The combination with an air brake mechanism including a train pipe, an auxiliary air reservoir, braking mechanism and a bralre locking device of an air. cylinder, a piston operable in the cylinder to move the locking device between functional and nonfunctional positions, a valve housing having air connection with the cylinder, the train line and auxiliary reservoir and having an air exhaust port therein, valves and control mechanism therefor in ,said housing operable under the influence of pressure of air in the auxiliary reservoir to move the valves to ad mit air into the cylinder from the train line to actuate the piston to retain the locking device in non-functional position so long as the pressure of air in the auxiliary reservoir remains above a predetermined amount and to release the air from the cylinder and close ofi the train line connection when the pressure falls below said predetermined amount to thereby permit retraction of the piston and movement of the locking device int-o functional position to retain the brakes set.

2. The combination with an air brake mechanism of the character described in cluding a train pipe, an auxiliary reservoir braking mechanism and a brake locking def- Vice of an air. cylinder, a piston operable outwardly in the cylinder to move the locking device from functional to non-functional position, a valve housing, a flexible diaphragm disposed within the housing, a con duit connecting the housing at one side oi the diaphragm with the auxiliary reservoir whereby the diaphragm sustains the pressure or air in the latter, a conduit connecting the housing at the other side of the diaphragm with the train line; said housing having. an air exhaust port and having chan` nels connecting the air cylinder with the conduit to the t ain line and with said exhaust port, valve members for controlling thev passage of air through said channels from the train line to the cylinder` and from the cylinder to the exhaust port, yieldable means for retaining the valve between the train line and cylinder closed and for sustaining the diaphragm against deflection as long as pressure in the auxiliary reservoir is below a certain amount and a valve stem operable by deflection of the diaphragm to adjust the valve mechanism to close the exhaust and to admit air from the train line to the air cylinder to actuate the piston outwardly.

3. lThe combination with an air brake mechanism of the character described including a train pipe, an auxiliary reservoir braking' mechanism and a brake locking deyvice of an air cylinder, a piston operable `whereby the diaphragm sustains the pressure of air in the latter, a conduit connecting the housing at the other side of the diaphragm with the train line; said housing having an air exhaust port and having channels connecting the air cylinder with the conduit to the train line and with said exhaust port, valve members for controlling the passage of air through said channels from the train line to the cylinder and from the cylinder to atmosphere, a spring yieldably retaining the valve between the train line conduit and cylinder in closed position and the valve between the cylinder and ex* haust port open, a spring for sustaining the diaphragm against reflection before a predetermined air pressure has been reached in the auxiliary reservoir and a valve stem engaging with the diaphragm and adapted to be moved by deflection of the latter to shift the valves to close the exhaust and openthe channel between train line conduit and cylinder to actuate the piston outwardly, and means for adjusting the sustainin pres` sure of said spring against the diap iragm.

4a The combination. with an air braise mechanism of the character described comprising an auxiliary reservoir, a train pipe, bralvgking mechanism and a brake locking device, of an air cylinder, a piston in said cylinder operable to control the locking device, a valve housing, a conduit connecting one end of the housing with the train line, a sleeve threaded part Way into the other end of the housing, a fitting threaded onto the outer portion of the sleeve, a cap applied to the fitting, a flexible diaphragm clamped between the itting and cap, a conduit con` necting the auxiliary reservoir and cap whereby the diaphragm sustains the pressure of the latter and is caused to expand and contract in accordance with Variation of pressure in the auxiliary reservoir; said valve housing having an exhaust port and an air channel between the said port and the connection with the train line conduit provided with spaced, valve seats facing outwardly from each other and a connecting channel leading therefrom from between said seats into the'air cylinder, lvalve members adapted to said seats and having engaging stems whereby the seating or either valve unseatsthe other, a spring for urging the train line valve to closed position and the exhaust Valve to open position, and a valve actuating stem having a head portion seated against said diaphragm whereby inward deflection of the diapl'iragm'reverses-the position o the Valves so as to admit air to actuate the piston outwardly and a spring bearing against said seat and litting to resist deliection of the diaphragm and variable in its tension by adjustment of the sleeve into or from the housing.

Signed at Tacoma, Pierce County, Washing-ton7 this 5th day of December, 1924.

BERNHARD W. WESTBO. 

